At least 16 people, including 13 police conscripts, were injured in a bomb blast in the Egyptian Nile Delta city of Tanta in the vicinity of a police training centre, the interior ministry said on Saturday.
"The bomb was planted in a motorcycle parked near the centre and the area has been cordoned off and is being combed by security forces," the ministry said in a statement.
A health ministry official in Tanta said all the injured are receiving treatment in hospital, including three civilians.
Five of the injured are in critical condition.
Militant group Lewaa Al-Thawra has claimed responsibility for the attack in an online statement, claiming on Twitter that the bombing resulted in "dozens of deaths and injuries, and the safe withdrawal of our fighters after accomplishing the operation."
Lewaa Al-Thawra has claimed responsibility for several attacks on security forces in recent months.
The group said it had murdered a high-ranking army officer in Dahshur, south of Cairo, in October 2016 and claimed responsibility for an attack on a security checkpoint in Menoufiya governorate, where two policemen were killed and five were injured, two months earlier.
Egypt has been battling an entrenched Islamist insurgency for several years in North Sinai, with hundreds of security forces killed in militant attacks.
Militant attacks have also been carried out in Cairo and other governorates.